What’s the best URL structure for Anspress in terms of SEO?

I have a question about SEO. I setup my URLS like this:

http://URL.com/questions/ – my Anspress page

http://URL.com/question/ – for each individual question

I stripped away the /questions/ from the individual page but is this bad for user friendliness?

What’s the best URL structure? I notice Quora just has: http://quora.com/what-is-the-best-beach-in-columbia

Is that structure possible to copy?